Let $P$ and $Q$ be constants. The graphs of the lines $x + 5y = 7$ and $15x + Py = Q$ are perpendicular and intersect at the point $(-8,3).$ Enter the ordered pair $(P,Q).$

Guest Jun 28, 2020

#1**+4 **

HInt: If they are perpendicular, then their slopes are the negative reciprocrals of each other.

amazingxin777 Jun 28, 2020